Sir Tim said he and his co-creators of the web began with
"utopian" hopes that it could bring the world closer together and
breakdown borders.

He said on Monday: "The assumption was if we gave humanity an
open space to play with, good things would happen," referring to
the creation of the world wide web.

"Last year, a lot of people did a re-think."

Sir Tim seemed to imply that the EU referendum and US
presidential elections changed his position. Both were
characterised by the spread of negative, often fake, stories on
networks like Facebook and Twitter.

He said: "Look at Twitter, is this actually a net good for the
planet?"

Sir Tim said that "nasty ideas" appear to spread faster on the
social network than positive messages, saying: "We have to think
about the effect." He added that he thought both Facebook and
Twitter themselves were reassessing how to regulate their
platforms.

Sir Tim moved from discussing Twitter to talking about political
advertising on social networks more generally. He said he is
worried by the fact that targeted advertising on social networks
allows politicians to advertise one thing to one person while
saying the complete opposite to someone else, effectively just
telling people what they want to hear in order to win power.

Sir Tim said: "Should we introduce a rule that if you're a
political organization, you may not target?"

"We need to re-think how we've built society on top of this web
thing," he concluded.

Computer scientists Sir Tim submitted a proposal to CERN for what
would become the world wide web on March 12, 1989, and is widely
seen as its creator. He is now the founding director of the World
Wide Web Foundation.